Mycelium Bitcoin Wallet

[molecular]

Would BIP32 be an option for mycelium?

I really don't like the single address (well, multiple single address) approach any more. It's just not good for anyones privacy.

I know this would be a huge change, both on the usability side as well as on your server infrastructure, but is it something you have considered and why did you decide against it? Are the reasons related to the bitcoincard somehow?

[RGBKey]

Would BIP32 be an option for mycelium?

I really don't like the single address (well, multiple single address) approach any more. It's just not good for anyones privacy.

I know this would be a huge change, both on the usability side as well as on your server infrastructure, but is it something you have considered and why did you decide against it? Are the reasons related to the bitcoincard somehow?

I second this

[Jan]

Christmas is over, and I hope you had a good one!

Would BIP32 be an option for mycelium?

I really don't like the single address (well, multiple single address) approach any more. It's just not good for anyones privacy.

I know this would be a huge change, both on the usability side as well as on your server infrastructure, but is it something you have considered and why did you decide against it? Are the reasons related to the bitcoincard somehow?

BIP32 is part of the plans for Mycelium, but as you say it is a big change, and we simply haven't gotten there yet. Our focus right now are features that allow new users to discover bitcoin and make it easy to get some coins (get their feet wet).
Andreas and I working on Mycelium full time, but we can see that we really need some more man-power, in particular developers. So if you are a skilled developer who is not afraid of Java and Android, and live in the Vienna neighborhood, send me a PM.

[dillpicklechips]

Are there plans to allow turning an old phone into a cheap hardware wallet? Have some private keys exist on a phone (with some type of phrase to restore them in case the phone dies) that is disconnected from everything permanently and it just signs transactions using qr codes?

[Newar]

Are there plans to allow turning an old phone into a cheap hardware wallet? Have some private keys exist on a phone (with some type of phrase to restore them in case the phone dies) that is disconnected from everything permanently and it just signs transactions using qr codes?

There is (was?):

https://bitcointalk.org/index.php?topic=210371.0

[molecular]

Christmas is over, and I hope you had a good one!

Would BIP32 be an option for mycelium?

I really don't like the single address (well, multiple single address) approach any more. It's just not good for anyones privacy.

I know this would be a huge change, both on the usability side as well as on your server infrastructure, but is it something you have considered and why did you decide against it? Are the reasons related to the bitcoincard somehow?

BIP32 is part of the plans for Mycelium, but as you say it is a big change, and we simply haven't gotten there yet. Our focus right now are features that allow new users to discover bitcoin and make it easy to get some coins (get their feet wet).
Andreas and I working on Mycelium full time, but we can see that we really need some more man-power, in particular developers. So if you are a skilled developer who is not afraid of Java and Android, and live in the Vienna neighborhood, send me a PM.

If I wasn't fully booked I'd probably jump on this offer. Couple months of Vienna working on a bitcoin wallet sounds nice.

It's good to hear you're on BIP32 integration.

I hope you will also consider integrating import of an extended public key into the address book so we can use that for recurring payments as described in this use case.

[arctos]

Any updates on message signing with mycelium? copy/paste buttons on the gui would be handy too (for message signing, and generally copying addresses)

[Kazimir]

Fee
The fee is calculated to be 0.0001 for each 1000 bytes of transaction size. This way the fee matches the minimum relay fee enforced by bitcoin nodes. If you go below that you risk that your transaction gets stuck in the network and never confirms. If we allow users to go below that, and blame it on us when their transactions get stuck.

I totally get your point.

Nonetheless, can you please (only in Expert mode, and perhaps with the information from your quote above as warning) add the possibility to customize the fee? How about: in Export mode by default still use 0.1 mBTC per 1000 bytes, but make it editable, and mention "recommended fee = xxx" in the edit fee screen/popup.

There are many occasions where I really don't care if a tx gets somewhat delayed or not (when transferring funds to myself, for example) and in Expert mode, one can be assumed to understand the difference.

[Rassah]

I second this. Sometimes I just want to move funds between my own accounts. Besides, with merchant services options coming out soon, you guys are having to work on custom set fees, anyway, right?...

[tinus42]

Is there a way to get rid of the "backup missing" message? Why do you need to print off the PDF and then scan it in to verify? I don't want to make a print of it.

[Jan]

Fee
The fee is calculated to be 0.0001 for each 1000 bytes of transaction size. This way the fee matches the minimum relay fee enforced by bitcoin nodes. If you go below that you risk that your transaction gets stuck in the network and never confirms. If we allow users to go below that, and blame it on us when their transactions get stuck.

I totally get your point.

Nonetheless, can you please (only in Expert mode, and perhaps with the information from your quote above as warning) add the possibility to customize the fee? How about: in Export mode by default still use 0.1 mBTC per 1000 bytes, but make it editable, and mention "recommended fee = xxx" in the edit fee screen/popup.

There are many occasions where I really don't care if a tx gets somewhat delayed or not (when transferring funds to myself, for example) and in Expert mode, one can be assumed to understand the difference.

The thing is that your transaction may not only "get somewhat delayed", it may never confirm at all. By paying 0.0001 for each 1000 bytes of transaction size (round up) it stays above the minimum relay fee required by nodes relaying the transaction to miners. Those are the rules of the network.
If we don't follow those rules users will experience transactions getting stuck. "freeing" your coins after that can be a nightmare, there are many threads on this forum on this topic. This will hit us (the developers) with a slew of angry users, as they will blame the wallet, and I really hate having angry users.

Fees in Bitcoin are quite complex and most users who consider themselves experts do not understand how it works.

All that said there is something we can do. The rules of the relaying nodes are not there to guarantee the miner some mining profit. The rules are there to limit transaction spam... a DOS attack filter, that prevents someone to send transactions to himself indefinitely, filling up the memory pool of relaying nodes. When the relay rules were introduced a portion of the memory pool / block size was reserved for what is called priority transactions. In short a transaction gets a priority according to the "age" of its inputs. If the "age" is sufficiently "old" (details here). Nodes will relay a priority transaction with a zero fee. Relaying does not guarantee inclusion in a block, and if the network continues to grow without the 1 MB block limit rising (or some other technical advancement) then the fees are bound to rise above the minimum relay fee.

Until now Mycelium has not considered zero fee high priority transactions. Something to work on.

[Jan]

I second this. Sometimes I just want to move funds between my own accounts. Besides, with merchant services options coming out soon, you guys are having to work on custom set fees, anyway, right?...

I am not certain what you mean by "merchant services options".
In the fee space bitcoin-qt 0.9 will have some changes for getting a "fee market" going, which will calculate fees dynamically depending on fees paid in previous blocks. We will implement something along those lines. Here are some of my thoughts on this topic: https://bitcointalk.org/index.php?topic=166302.0

[Jan]

Any updates on message signing with mycelium? copy/paste buttons on the gui would be handy too (for message signing, and generally copying addresses)

Message signing is in the works.

[Jan]

Is there a way to get rid of the "backup missing" message?

The "backup missing" message is shown as long as you have a private key which was created by the wallet and which hasn't been backed up with verification.
Private keys imported (e.g. from paper) are verified by default, as you have proven to have an external source (backup) of the key. One way to get around this is to create a private key by external means and import it to the wallet, and then delete the automatically generated initial key.

Why do you need to print off the PDF and then scan it in to verify? I don't want to make a print of it.

You don't have to print the PDF. You can scan it from the display of your computer.
The reason for verifying is that you may have made a mistake when you made the backup.

• The PDF send to a wrong email address, or you accidentally deleted it before printing ...
• The password not written down correctly/readable

A backup that does not work is worse than no backup at all, as you think you are good.

More coins have been lost due to lack of backups than due to theft. We really want to help users not loosing coins.

[westkybitcoins]

The thing is that your transaction may not only "get somewhat delayed", it may never confirm at all. By paying 0.0001 for each 1000 bytes of transaction size (round up) it stays above the minimum relay fee required by nodes relaying the transaction to miners. Those are the rules of the network.
If we don't follow those rules users will experience transactions getting stuck. "freeing" your coins after that can be a nightmare, there are many threads on this forum on this topic. This will hit us (the developers) with a slew of angry users, as they will blame the wallet, and I really hate having angry users.

I support keeping the mandatory minimum 0.0001 fee. There are plenty or reasons for it to stay, and it's worth it to maintain the simplicity of the app.

Message signing is in the works.

Nice!

Is there a way to get rid of the "backup missing" message?

The "backup missing" message is shown as long as you have a private key which was created by the wallet and which hasn't been backed up with verification.
Private keys imported (e.g. from paper) are verified by default, as you have proven to have an external source (backup) of the key. One way to get around this is to create a private key by external means and import it to the wallet, and then delete the automatically generated initial key.

The "backup missing" message may look annoying, but I think it makes sense to not change the requirements for removing it.

[Rassah]

I second this. Sometimes I just want to move funds between my own accounts. Besides, with merchant services options coming out soon, you guys are having to work on custom set fees, anyway, right?...

I am not certain what you mean by "merchant services options".

Where the merchant requests the transaction, the transaction is signed by the sender and transferred to the merchant, and the merchant verifies it before broadcasting it to the network. Thus the merchant is able to demand a certain custom sized fee, and decline a transaction if the fee they want is not included.
Regarding zero fees, why not do what blockchain.info does, and allow zero fee transactions, and if they don't get confirmed after 24 hours, scrap the transaction and make the coins spendable again.

[molecular]

I second this. Sometimes I just want to move funds between my own accounts. Besides, with merchant services options coming out soon, you guys are having to work on custom set fees, anyway, right?...

I am not certain what you mean by "merchant services options".

Where the merchant requests the transaction, the transaction is signed by the sender and transferred to the merchant, and the merchant verifies it before broadcasting it to the network. Thus the merchant is able to demand a certain custom sized fee, and decline a transaction if the fee they want is not included.
Regarding zero fees, why not do what blockchain.info does, and allow zero fee transactions, and if they don't get confirmed after 24 hours, scrap the transaction and make the coins spendable again.

Is it so easy to scrap a tx? If it's in everyones mem-pool, would it likely get replaced by a double-spend one with a fee?

[Jan]

I am not certain what you mean by "merchant services options".

Where the merchant requests the transaction, the transaction is signed by the sender and transferred to the merchant, and the merchant verifies it before broadcasting it to the network. Thus the merchant is able to demand a certain custom sized fee, and decline a transaction if the fee they want is not included.
...

Ahh, yes, the payment protocol. We cannot really rely on it right now as it is not really used much yet. Going forward this is likely to change.

[Jan]

I second this. Sometimes I just want to move funds between my own accounts. Besides, with merchant services options coming out soon, you guys are having to work on custom set fees, anyway, right?...

I am not certain what you mean by "merchant services options".

Where the merchant requests the transaction, the transaction is signed by the sender and transferred to the merchant, and the merchant verifies it before broadcasting it to the network. Thus the merchant is able to demand a certain custom sized fee, and decline a transaction if the fee they want is not included.
Regarding zero fees, why not do what blockchain.info does, and allow zero fee transactions, and if they don't get confirmed after 24 hours, scrap the transaction and make the coins spendable again.

Is it so easy to scrap a tx? If it's in everyones mem-pool, would it likely get replaced by a double-spend one with a fee?

Correct. The a relaying node (or miner for that matter) will regard another transaction using the same inputs as a double spend. The transaction has to get removed from the memory pool of receiving nodes before you can send out a version with a higher fee using some of the same inputs. This happens naturally over time (as nodes get rebooted) but it is hard to tell when that will be. So basically some of your inputs are stuck.

(real) Transaction replacement was part of the original Bitcoin protocol, but was disabled pretty early on (if it was ever fully enabled).

[Rassah]

Can you ask how blockchain.info does it?